KR101287486B1 - Apparatus for removing of unburned carbon from fly ash and relevant removing method - Google Patents

Abstract

The present invention provides a method for removing unburned carbon in fly ash, which can reduce the cost of equipment and enable stable performance adjustment according to the properties of the fly ash.

Water is added to the fly ash to form a slurry, a collecting agent is added, feeding to a stationary mixer 4 or a venturi tube 24 or the like to impart shear force, and a foaming agent is added to generate bubbles, and the bubbles are not smoked. Float by attaching carbon. The foaming agent and air may be supplied to the stationary mixer or the like together with the slurry and the collecting agent. The number of series use of a stationary mixer etc. increases and decreases according to the property of a fly ash, and the number of parallel use of a stationary mixer etc. increases or decreases according to a required processing capability. The stationary mixer is provided with a plurality of guide vanes 4d, a guide vane chamber 4b for converting a slurry or the like into a spiral flow, and a current cutter chamber for providing shear force to the slurry with a plurality of mushroom protrusions 4e ( What has 4c) can be used.

Fly ash, unburned carbon, scavenger, mixer, foaming agent.

Description

Unburned carbon removal device and method of removal in fly ash {APPARATUS FOR REMOVING OF UNBURNED CARBON FROM FLY ASH AND RELEVANT REMOVING METHOD}

The present invention relates to an apparatus and a method for removing unburned carbon in fly ash, in particular, to effectively remove unburned carbon from fly ash generated in a coal-fired power plant, and to effectively use the fly ash after removing the unburned carbon and unburned carbon. An apparatus and method are provided.

Fly ashes generated from coal-fired power plants are used for raw materials of cement and artificial lightweight aggregates and admixtures for concrete. However, when used as a mixed admixture of concrete, unburned carbon in the fly ash absorbs an AE water reducing agent and the like and degrades workability of the concrete. In addition, unburned carbon rises during the casting of concrete, causing black parts to occur in other parts of the concrete. Furthermore, there was also a problem that the quality of artificial lightweight aggregates deteriorated when there was a large amount of unburned carbon in fly ash. Therefore, although fly ash with a small amount of unburned carbon can be used for cement raw materials, fly ash with a high content of unburned carbon cannot be effectively used, and was thus disposed as industrial waste.

Therefore, in order to effectively remove unburned carbon from the fly ash having a high content of unburned carbon, Patent Literature 1 adds water to the fly ash to form a slurry, and then adds a collecting agent, and penetrates the cylindrical body in the axial direction. After supplying a slurry and a collecting agent to the submerged stirring apparatus provided with the rotating shaft to be divided, the main body divided into the axial direction, and the stirring blade fixed to the rotating shaft to rotate inside each room, a foaming agent is provided, A method of removing unburned carbon in fly ash is described, wherein bubbles are generated while stirring and the unburned carbon of the fly ash is attached to the bubbles to float.

According to this method, it is possible to significantly reduce the unburned carbon powder by applying a shear force to the original fly ash slurry containing unburned carbon to which the collecting agent is added before the flotation process, and to obtain a fly ash having about 0.5% of unburned carbon powder. It becomes possible. Moreover, since the collection agent added at this time can use common things, such as kerosene, and the usage amount of a collection agent can also be reduced, there exists little effect that kerosene etc. remain in fly ash as a product, and the post-processing after a flotation process is easy. Bring.

Patent Document 1: Japanese Patent No. 3613347

(Problems to be Solved by the Invention)

However, in the conventional method for removing unburned carbon in the fly ash, there is a problem that the apparatus cost becomes expensive because a relatively large in-water stirring apparatus is used in applying the shear force to the fly ash slurry. In addition, there is a problem that it is difficult to adjust the processing capacity according to the properties of the fly ash, since it is common to provide one of the liquid stirring apparatuses in the unburned carbon removal system.

Accordingly, the present invention has been made in view of the problems of the prior art, and provides a device and a method for removing unburned carbon in fly ash, which can reduce the device cost and make stable performance adjustment according to the properties of the fly ash. It aims to do it.

(MEANS FOR SOLVING THE PROBLEMS)

In order to achieve the above object, the present invention relates to an unburned carbon removing device in fly ash, comprising: a slurry including a fly ash and a conduit having a stationary mixer or compression section for imparting shear force to a collecting agent; A bubble is generated while stirring the foaming agent and the foaming agent, and the buoy group which floats and attaches unburned carbon of the said fly ash to the said bubble is characterized by the above-mentioned.

According to the present invention, the shearing force is applied to the slurry and the collecting agent by using a static mixer or a compression line having a stationary mixer or a compression unit, which is relatively small and does not have a moving part. In this case, the unburned carbon of the fly ash can be attached to this bubble and floated, so that the apparatus cost can be kept low in removing the unburned carbon in the fly ash.

In addition, the present invention relates to an unburned carbon removal device in a fly ash, comprising: a slurry comprising a fly ash, a conduit having a stationary mixer or a compression unit for imparting shear force to the collector and the foaming agent; It generates a bubble while stirring, characterized in that it comprises a buoy group to float by attaching the unburned carbon of the fly ash to the bubble. Thereby, similarly to the above invention, in removing the unburned carbon in the fly ash, the apparatus cost can be kept low.

In the unburned carbon removal device in the fly ash, an air supply device for supplying air to a pipeline having a stationary mixer or a compression section may be provided. By introducing air into a stationary mixer or the like, the surface of the unburned carbon can be modified using a cavitation effect in the inside of the stationary mixer and the like, and the introduced air can also be used as air for barges in a barge.

In the unburned carbon removal device in the fly ash, a plurality of pipes having the stationary mixer or the compression section can be arranged in series or in parallel. By increasing or decreasing the number of stationary mixers to be arranged in series, stable performance adjustment can be performed even if the properties of the fly ash change. Furthermore, by increasing or decreasing the number of stationary mixers to be arranged in parallel, even if the required processing capacity of the fly ash changes, stable performance adjustment can be performed.

In the unburned carbon removal device in the fly ash, a plurality of the floaters can be arranged in series, and a conduit line having the stationary mixer or the compression section can be arranged between the adjacent floaters. Unrefined carbon can be separated from the fly ash with high efficiency by repeatedly applying the shear force to the slurry, the collecting agent, and the like.

The stationary mixer is provided with a guide vane chamber for converting a supplied fluid into a spiral flow with a plurality of guide vanes, and a current cutter for providing a shear force to the fluid converted into a spiral flow by installing a plurality of mushroom protrusions. It can be comprised so that a thread may be provided.

In addition, the conduit having the compression portion may be composed of a venturi tube or an orifice.

In addition, the present invention is a method for removing unburned carbon in fly ash, wherein water is added to the fly ash to form a slurry, and a collecting agent is added to the slurry, and the slurry and the collecting agent are supplied to a pipe having a stationary mixer or a compression section to improve shear force. It is characterized in that the foaming agent is added to the slurry and the collecting agent to which the shearing force is applied, bubbles are generated while stirring, and the unburned carbon of the fly ash is attached to the bubbles to float.

According to the present invention, a shearing force is applied to the slurry and the collecting agent by using a stationary mixer or a compression line having a relatively small, moving part, and then foaming is generated by adding a foaming agent and stirring. Since the unburned carbon of fly ash can be attached and floated, the apparatus cost can be kept low.

Furthermore, the present invention is a method for removing unburned carbon in fly ash, wherein water is added to the fly ash to form a slurry, and a collecting agent and a foaming agent are added to the slurry, and the slurry, the collecting agent and the foaming agent are used as a stationary mixer or compression unit. After supplying a shearing force by supplying to a pipe having a pipe, bubbles are generated while stirring, and the unburned carbon of the fly ash is attached to the bubbles to float. Thereby, similarly to the above invention, in removing the unburned carbon in the fly ash, the apparatus cost can be kept low.

In the method of removing unburned carbon in the fly ash, air can be introduced into a pipeline having the stationary mixer or compression section, and the air introduced into the flotation machine is modified while the surface of the unburned carbon is modified using a cavitation action. It can also be used as linear air.

In the method for removing unburned carbon in the fly ash, the number of series uses of the pipeline having the stationary mixer or the compression section can be increased or decreased according to the change in the properties of the fly ash. Thereby, stable performance adjustment can be performed even if the property of a fly ash changes.

Further, in the method of removing unburned carbon in the fly ash, the number of parallel uses of the pipe having the stationary mixer or the compression unit can be increased or decreased depending on the required processing capacity of the fly ash. Thereby, stable performance adjustment can be performed even if the required processing capability of a fly ash changes.

Furthermore, in the method for removing unburned carbon in the fly ash, it is possible to determine the replacement timing of the conduit having the stationary mixer or the compression section by the pressure loss before and after the conduit having the stationary mixer or the compression section. It is possible to appropriately grasp the wear situation of each part of the pipeline having the static mixer or the compression section by the abrasive ash particles having wearability, and to properly maintain the system.

(Effects of the Invention)

As mentioned above, according to this invention, in removing unburned carbon from a fly ash, it becomes possible to suppress the increase of apparatus cost, and to perform stable performance adjustment according to the property of a fly ash. In addition to this, the effect of creating a new surface of the fly ash particles can result in a more robust reaction with the cement hydrate when the fly ash is added to the cement and cured.

1 is a flow chart showing an example of a system to which an unburned carbon removal apparatus and a removal method in a fly ash according to the present invention are applied.

Fig. 2 shows an OHR mixer as an example of a stationary mixer used for the unburned carbon removal device in fly ash according to the present invention, where (a) is a longitudinal cross-sectional view and (b) is a cross-sectional view.

3 is a flow chart showing an embodiment of the unburned carbon removal apparatus in the fly ash according to the present invention.

4 is a flowchart showing another embodiment of the unburned carbon removal apparatus in the fly ash according to the present invention.

5 is a flow chart showing another embodiment of the unburned carbon removal apparatus in the fly ash according to the present invention.

It is sectional drawing which shows the venturi tube as an example of the pipeline which has a compression part used for the unburned carbon removal apparatus in fly ash which concerns on this invention.

<Code description>

One… Fly ash tank,

2… Slurry tank,

3 ... Pump,

4 (4A-4D)... Stationary mixer,

4a ... main body,

4b... Guide vanes,

4c ... Current cutter thread,

4d… Guide vanes,

4e… spin,

4f... Entrance,

4 g... Outlet,

5 ... Pump,

6... Kerosene tank,

7 ... Adjustment Tank,

8… Pump,

9... Foam tank,

10... Pump,

11 (11A-11D)... Boogie,

12... Pump,

13... Solid-liquid separator,

14... dryer,

15... Bug filters,

16 ... Hot Air,

17... Pump,

18... Filter press,

24 ... Venturi Tube,

24a ... Cylindrical pipeline,

24b... Compressor,

24c... pipeline

1 shows an example of the configuration of a system to which a device and a method for removing unburned carbon in a fly ash according to the present invention are largely divided into a fly ash tank 1 and a fly ash supplied from a fly ash tank 1. A slurry tank 2 for adding water to ash to produce a slurry, and a static mixer 4 for adding a collecting agent to the slurry and then applying shear force to the slurry and the collecting agent to modify the surface of unburned carbon, and the like (4). (4A to 4C)), and a bubbling machine 11 which separates unburned carbon by adding a foaming agent to the slurry to generate bubbles and attaching and floating the unburned carbon of the fly ash to the bubble. From a solid-liquid separator 13 for solid-liquid separating tailing, a dryer 14 for drying the cake from the solid-liquid separator 13 to obtain a dried fly ash (product), and a flotation machine 11 And a filter press 18 for solid-liquid separation of the frost to obtain unburned carbon.

The slurry tank 2 is provided for producing a slurry with fly ash and water, and has stirring blades for stirring the slurry therein. The fly ash tank 1 and the water supply apparatus are provided in front of this slurry tank 2, and the pump 3 for sending a slurry to the stationary mixer 4 is arrange | positioned at the rear end of the slurry tank 2.

The stationary mixer 4 is provided to modify the surface of unburned carbon by applying shear force to the slurry and the collecting agent, or to break the particles contained in the slurry very finely. As an example of this static mixer 4, there is a static mixer shown in Fig. 2 (manufactured by Seika Sangyo Co., Ltd., OHR line mixer). In this stationary mixer 4, the cylindrical body 4a is divided into a guide vane chamber 4b and a current cutter chamber 4c, and a plurality of guide vanes 4d are included in the guide vane chamber 4b, and a current cutter. A plurality of mushroom-shaped protrusions 4e are erected on the thread 4c.

By the above configuration, the two fluids introduced from the inlet portion 4f into the guide vane chamber 4b are converted into spiral flows by the guide vanes 4d. It moves inward, and the projections 4e of the current cutter chamber 4c form the outer heavy fluid layer and the inner hard fluid layer as ultrafine particle groups, and the microparticle group of the heavy fluid and the microparticles of the hard fluid. The groups react in a violent and continuous collision with each other.

As shown in FIG. 1, a kerosene tank 6 for storing kerosene as a collecting agent and a pump 5 for supplying kerosene to the stationary mixer 4 are provided at the front end of the stationary mixer 4.

The adjustment tank 7 adds the foaming agent supplied from the foaming tank 9 through the pump 8 to the slurry and the collecting agent from the stationary mixer 4, and mixes these, and has a stirring blade inside. At the rear end of the adjusting tank 7, a pump 10 for sending the slurry to the subsidiary machine 11 is arranged.

The floater 11 attaches the unburned carbon of the fly ash to the bubble and floats it to separate the fly ash from which the unburned carbon and the unburned carbon are removed. An air supply device for generating bubbles above the floater 11 is provided. Is installed. At the rear end of the buoy 11, a pump 12 for sending tailings to the solid-liquid separator 13 is arranged.

The solid-liquid separator 13 is provided for solid-liquid separation of the tailing including the fly ash discharged from the buoy 11, and separates the tailing into a cake and water.

The dryer 14 is provided for drying the cake supplied from the solid-liquid separator 13 using the hot air from the hot stove 16, and the dried cake, that is, the fly ash (product), is used as a cement mixture or the like.

The bug filter 15 is provided for recovering fine powder from the dryer 14, and the recovered fine powder is also used as a cement mixture or the like.

The filter press 18 is provided for solid-liquid separation of the process containing unburned carbon from the flotation machine 11, and the unburned carbon contained in the separated cake can be used as fuel. The water discharged from the filter press 18 can also be reused in the slurry tank 2 or the like through the pump 17.

The hot stove 16 is provided to supply hot air to the dryer 14, and unburned carbon discharged from the filter press 18 may be used for drying.

Next, a method of removing unburned carbon in the fly ash according to the present invention using the above system will be described with reference to FIG. 1.

The fly ash is fed from the fly ash tank 1 to the slurry tank 2 and mixed with water to produce a slurry. Here, the fly ash concentration in the slurry is adjusted in the range of 3 to 50% by weight.

The slurry comprising the fly ash in the slurry tank 2 is then fed to the stationary mixer 4 via a pump 3. On the other hand, kerosene as a collecting agent is supplied from the kerosene tank 6 to the stationary mixer 4 via the pump 5. In addition to kerosene, general collecting agents such as diesel oil and heavy oil can be used. The addition amount of this collector is adjusted to the range of 5-100 weight% of the amount of unburned carbon in a fly ash.

In the next stationary mixer 4, the slurry and the collecting agent are sheared or the particles contained in the slurry are crushed very finely. Processes, such as the provision of this shear force, are the feature part of this invention. For example, the shearing force can be applied using the static mixer 4 shown in FIG. 2. In the stationary mixer 4, the flow of the slurry and the collecting agent supplied from the inlet 4f is converted into spiral flow by the guide vane 4d of the guide vane chamber 4b, and the current cutter chamber 4c. The projection 4e gives a shearing force and breaks the particles contained in the slurry very finely. The slurry and the collecting agent having been subjected to the shearing force or the like are discharged from the outlet portion 4g and supplied to the adjustment tank 7.

As described above, the application of the shear force to the fly ash slurry and the collecting agent is performed to improve the flotation floatability by modifying the surface of the unburned carbon, etc., and thus the unburned carbon is adsorbed to the collecting agent. And when performing a barge using the floater 11, the unburned carbon adsorbed to the collecting agent adheres to the bubble and floats. In this way, the floating-line floating property of unburned carbon can be improved.

Next, as shown in FIG. 1, the process containing the unburned carbon discharged | emitted from the buoy 11 is carried out solid-liquid separation by the filter press 18, and unburned carbon is collect | recovered. The dehydrated water in the filter press 18 is supplied to the slurry tank 2 through the pump 17 and added to the new fly ash or reused in the parcel when attaching unburned carbon to the bubbles in the buoy 11. can do.

On the other hand, the tailing including the fly ash from the flotation machine 11 is solid-liquid separated in the solid-liquid separator 13, and when the cake has a lot of moisture, the unburned carbon discharged from the filter press 18 is heated in the hot stove 16. Using the hot air obtained by burning, the cake is dried in the dryer 14, and a fly ash as a product in which unburned carbon powder is 1% by weight or less can be used for a cement mixture or the like. The fine powder recovered by the bug filter 15 can also be used as a cement mixture or the like.

In addition to the above-mentioned OHR mixer, the stationary mixer 4 may include a resistor arranged in an arm shape in an inclined state toward the downstream side, or a type of dividing, inverting and mixing by a torsion element.

In addition, in the said embodiment, a foaming agent is added to the adjustment tank 7 of the rear end of the stationary mixer 4 (4A-4C), and a bubble is generated while stirring, and the fly ash is not smoked to the bubble in the floater 11. After the carbon was attached and floated, the foaming agent was supplied to the stationary mixer 4 (4A to 4C) together with slurry and kerosene as a collecting agent, and the shearing force was applied. Then, bubbles were generated while stirring them in the adjusting tank 7. In the group 11, the unburned carbon of the fly ash may be attached to the bubble and floated.

Moreover, in stationary mixers 4, such as OHR mixers, cavitation is likely to occur, and when air is introduced into the stationary mixers 4 as shown in Fig. 3, the surface of unburned carbon is utilized by using the cavitation action. The modified air can be used and the air introduced can also be used as the air for barges in the buoy 11.

Further, as shown in FIG. 4, the stationary mixers 4A and 4B are arranged in series over two stages, and air is introduced into the downstream of the stationary mixer 4A together with the foaming agent to improve the effect of modifying the surface of the unburned carbon. It is also possible to use the air introduced at a higher height as the air for barges in the buoy 11.

Furthermore, as shown in FIG. 5, a plurality of subsidiary units 11A to 11D are provided and arranged in the stationary mixers 4B, 4C, and 4D between each of the subsidiary units to fly fly ash from the subsidiary units 11A to 11D. By introducing the tailings included in this order, shearing force can be applied to the slurry and the collecting agent, and unburned carbon can be separated from the fly ash with high efficiency. Here, it is not necessary to add kerosene and a foaming agent to the floaters 11B to 11D, and only air is introduced.

Next, as another configuration example of the system to which the apparatus and method for removing unburned carbon in the fly ash according to the present invention is used, a case of using a conduit having a compression section instead of the static mixer of FIG. 1 will be described.

A conduit having a compression section is, for example, a conduit 24c whose pipe diameter increases in the flow direction of a slurry indicated by an arrow with a cylindrical conduit 24a and an arrow as a boundary between the compression section (a block) 24b. It is a venturi tube 24 which has.

When the venturi tube 24 is used, when the slurry and the collecting agent flow through the compression section 24b, the flow velocity becomes faster, the pressure decreases, the flow velocity of the slurry and the like decreases in the pipeline 24c, and the pressure increases. . As such, a rapid pressure change occurs in the slurry or the like flowing through the venturi tube 24, so that shear force is applied to the slurry, and the particles contained in the slurry can be broken very finely. By improving, it is possible to improve the flotation floating property of unburned carbon.

In addition, the piping which has a compression part which can be used in this invention is not limited to the said venturi tube 24, The thing using an orifice plate, etc. can also be used.

In addition, instead of the static mixer 4 shown in Figs. 3 to 5, a conduit having a compression section such as a venturi tube 24 can be used, and the same effect as in the case of using the static mixer 4 is achieved.

Claims (13)

A conduit with a static mixer or compression section for imparting shear force to the slurry comprising the fly ash and the collecting agent, An apparatus for removing unburned carbon in fly ash, comprising a flotation machine for generating bubbles while stirring the shearing force, the collecting agent, and the foaming agent, and attaching the unburned carbon of the fly ash to the bubble. A conduit having a slurry including a fly ash, a stationary mixer or compression unit for imparting shear force to the collecting agent and the foaming agent, An apparatus for removing unburned carbon in fly ash, comprising a flotation machine which generates bubbles while stirring the shear force-providing slurry, collecting agent, and foaming agent, and attaches unburned carbon of the fly ash to the bubble. The unburned carbon removal device according to claim 1 or 2, further comprising an air supply device for supplying air to the pipeline having the stationary mixer or the compression section. The unburned carbon removal apparatus in fly ash according to claim 1 or 2, wherein a plurality of pipes having the stationary mixer or the compression section are arranged in series or in parallel. The apparatus for removing unburned carbon in fly ash according to claim 1 or 2, wherein a plurality of said floaters are arranged in series and a pipe line having said stationary mixer or a compression section is disposed between said adjacent floaters. The static mixer of claim 1 or 2, wherein the stationary mixer is provided with a guide vane chamber for installing a plurality of guide vanes and converting the supplied fluid into a spiral flow, and a plurality of mushroom-shaped protrusions are installed and converted into spiral flow. An apparatus for removing unburned carbon in fly ash, comprising: a current cutter chamber for imparting shear force to the fluid. 3. The apparatus for removing unburned carbon in fly ash according to claim 1 or 2, wherein the conduit having the compression portion is a venturi tube or an orifice. Water is added to the fly ash to make a slurry, Adding a collecting agent to the slurry, Supplying the slurry and the collecting agent to a pipeline having a stationary mixer or a compression unit to impart shear force, A method of removing unburned carbon in fly ash, wherein a foaming agent is added to the slurry and collecting agent to which the shear force is applied, bubbles are generated while stirring, and the unburned carbon of the fly ash is attached to the bubble to float. Water is added to the fly ash to make a slurry, Adding a collecting agent and a foaming agent to the slurry, After supplying the slurry, the collecting agent and the foaming agent to a pipe line having a stationary mixer or a compression unit to impart shear force, bubbles are generated while stirring, and the unburned carbon of the fly ash is attached to the bubbles to float. Unburned carbon removal method in fly ash. 10. The method for removing unburned carbon in fly ash according to claim 8 or 9, wherein air is introduced into a conduit having the stationary mixer or the compression section. 10. The method for removing unburned carbon in fly ash according to claim 8 or 9, wherein the number of series uses of the pipeline having the stationary mixer or compression section is increased or decreased in accordance with the change of the fly ash properties. 10. The method for removing unburned carbon in fly ash according to claim 8 or 9, wherein the number of parallel uses of the pipeline having the stationary mixer or compression unit is increased or decreased according to the required processing capacity of the fly ash. 10. The method for removing unburned carbon in fly ash according to claim 8 or 9, wherein the timing of replacement of the pipeline with the static mixer or the compression section is determined by the pressure loss before and after the pipeline with the static mixer or the compression section. .

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